About Pipe Flow Lab

The thesis

Existing free pipe-flow calculators are mostly pump-vendor lead magnets (locked to their equipment), academic non-mobile sites, or simple stripped-down forms that ignore fittings. The audience — mechanical, civil, plumbing, and irrigation engineers — needs better: multi-segment systems, a fitting counter that doesn't make you look up K-factors in a PDF, temperature-aware fluid properties, and a real cost-of-friction estimator. That's what Pipe Flow Lab is.

Everything works from the URL bar. No login, no email gate, no popups. The calculator math is in a methodology page with cited sources. The fitting library is from Crane TP-410 and Cameron Hydraulic Data. Water properties are NIST IAPWS-IF97. The JS bundle is small and the calculator path has no third-party scripts on it.

What's free, what's planned

Free, today

• Pressure-drop calculator — multi-segment, fitting-aware, temperature-adjusted, with cost-of-friction estimator
• Hazen-Williams calculator with C-factor library and Darcy-Weisbach cross-check
• Darcy-Weisbach calculator with three friction-factor correlations side-by-side
• Fitting equivalents reference — searchable K and L/D table with a mini-calc
• Pump sizing calculator with NPSH-available helper and NEMA motor recommendation
• Pipe velocity check — sediment / safe / water-hammer band
• Four guides covering the math + design rules
• A methodology page with sources, formulas, and audit dates

On the roadmap

• Pump curve overlay — paste a manufacturer's pump curve, find the operating point
• Water-hammer transient calculator
• Pipe-sizing inverse mode (given allowable Δp + flow → recommend diameter)
• Slurry / two-phase corrections

Also from this team

We also run yardvolume.com — DIY landscape volume calculators for mulch, gravel, topsoil, and concrete. Different audience, same insistence on getting the math right.

Contact

Found a bug? Want to suggest a fluid for the library? Email [email protected]. Forum and LinkedIn engagement is the primary distribution channel — say hi if you spot us on r/MEPEngineering, Eng-Tips, or LinkedIn.